Troubleshooting code Po420 - 2001 Saturn L-Series

Pesky PO420 Codes - Eastern Catalytic

www.easterncatalytic.com/education/tech-tips/pesky-p0420-codes/

One of the most annoying is the persistent PO420 diagnostic code (Catalyst System ... not only shows its teeth when the catalytic converter is on the blink, but can also be ... Most, if not all, catalytic converter failures are caused by a problem or ...

P0420 Error Code: Catalyst System Efficiency Below ...

www.obd-codes.com/p0420

Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency ... If they have failed, it is likely due to something else that caused it to fail. ... the catalytic converter is broken or failed, it may be restricting the exhaust which will ...

explaining trouble codes po420 - po421 - Discount Catalytic ...

replace the cat converter

Go to google & type in ---OBD2 Codes
1998 honda accord PO420 etc

po420--- catalist efficiency below threshold--- possible fix. a po420 means that one or more of the following has happened. the easiest thing to do, is erase code with scanner. and see if it comes back. the engine coolant tempuature sensor may not be working properly, damaged exhaust manifold, or catalytic convertor may be bad. check 02 sensor also behind convertor towards rear. its really hard to say can be anyone off above!! but check 02 sensor first it may be bad.

Well, the po401 is saying is that the egr valve has restricted flow. After changing the egr and the tube, something else is causing the restriction. a more thorough diagnosis is recommended. The po420 code sounds like a possible catalyst failure or an o2 sensor failure.

I could go on and on about Po420 code but it's easyer to tell you to go to www.po420.com and everything you want to know and then some is there. Let me know if this was helpfull..4 thumbs up !

I have tow of the three requested codes. po300 is misfire detected at multiple cylinders. See po301-306 represent the cylinder # misfire. So 301 is cylinder #1 misfire.

po420 is Catalytic Converter Efficiency Failure

If the code has cleared on its own then you need to disconnect the battery and re-connect it. This will clear the codes out of the memory. If you don't want to do this you can go to an auto parts strore and have them hook the little computer up to your car and they can clear out the code as well.

P0420 is catalyst system efficiency below threshold (bank 1)

P0440 is evaporative emission control system malfunction

P0441 is evaporative emission control system incorrect purge flow

Replace the catalytic converter.